Gas-operated refrigerator having sealed combustion system

ABSTRACT

A heat-operated refrigerator heated by a gas burner and a heating flue associated therewith is disposed in a space having an apertured exterior side wall. The heating flue and burner form parts of a sealed combustion system which includes a first conduit for supplying all of the combustion supporting air to the burner to form a combustible gas mixture with gas supplied thereto and a second conduit for withdrawing all of the flue gases from the upper end of the flue. The ends of the first and second conduits removed from the burner and flue, respectively, are open and terminate in the apertured side wall, the open end of the first conduit serving as an inlet for ambient air and the open end of the second conduit serving as an outlet for flue gases. The flue gas outlet is disposed above the air inlet. The air inlet and flue gas outlet have the same cross-sectional areas and are flush with the outer surface of the exterior wall.

United States Patent Magnusson et a1.

[451 June 13, 1972 [72] Inventors: Olov 'Iage Magnusson, Bromma; Karl Gosta Lennart Kenneryd, Vallingby, both of Sweden [73] Assignee: Aktiebolaget Electrolux, Stockholm,

Sweden [22] Filed: Aug. 19, 1970 [21] Appl. No. 65,131

[30] Foreign Application Priority Data Sept. 12, 1969 Sweden ..l2566/69 [52] U.S. C1. ..62/476, 126/85 13, 126/307 R [51] Int. Cl ..F23j 11/00, F25b 15/00 [58] Field ofSearch ..126/85, 85 B, 307; 98/32, 62; 62/490, 476

[56] References Cited UNITED STATES PATENTS 1,736,871 1 H1929 Backstrom ..62/490 X 3,527,260 9/1970 Kimmel ..126/360 X 3,530,848 9/1970 Wilhoite ..126/85 B FOREIGN PATENTS OR APPLICATIONS 819,148 8/1959 Great Britain ..126/85 B 348,529 10/1960 Switzerland .126/85 B 930,248 7/1963 Great Britain..... 126/85 B Primary Examiner-Char1es J. Myhre Atlorney-Edmund A. Fenander [5 7] ABSTRACT A heat-operated refrigerator heated by a gas burner and a heating flue associated therewith is disposed in a space having an apertured exterior side wall. The heating flue and burner form pans of a sealed combustion system which includes a first conduit for supplying all of the combustion supporting air to the burner to form a combustible gas mixture with gas supplied thereto and a second conduit for withdrawing all of the flue gases from the upper end of the flue. The ends of the first and second conduits removed from the burner and flue, respectively, are open and terminate in the apertured side wall, the open end of the first conduit serving as an inlet for ambient air and the open end of the second conduit serving as an outlet for flue gases. The flue gas outlet is disposed above the air inlet. The air inlet and flue gas outlet have the same cross-sectional areas and are flush with the outer surface of the exterior wall.

11 Claims, 6 Drawing Figures PATENTEDJUN 13 I972 3, 668 889 sum 1 or 2 SHEET 2 OF 2 FIG.5

PATENTEDJUH 13 I972 GAS-OPERATED REFRIGERATOR HAVING SEALED COMBUSTION SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to gas-operated refrigerators for enclosed spaces, such as a permanent residential structure, for example, mobile homes like trailers and campers, and boats in which a gas burner and heating flue coacting therewith form parts of a sealed combustion system having a first conduit for supplying ambient air to the burner, such ambient air constituting all of the air supplied to the burner to form a combustible gas mixture with a combustible gas supplied thereto, and having a second conduit for conducting all of the flue gases from the flue outside the space.

2. Description of the Prior Art Sealed combustion systems of the kind referred to above have been employed for operating heat-operated refrigerators. However, sealed combustion systems heretofore employed have not been satisfactory due to the fact that the pressure of ambient air fluctuates and produces pressure changes which are reflected back through the system and often extinguish the burner flame. This has occurred in systems in which the ambient air inlet is relatively near to the burner and the flue gas outlet is located at a region removed from the air inlet and located at a region more or less convenient with respect to the upper end of the heating flue. This is objectionable because, although the supply of gas will be shut off automatically when the burner flame is extinguished, the food stored in the refrigerator may spoil due to lack of refrigeration.

For this reason efforts have been made to overcome this difficulty by locating the air inlet and flue gas outlet adjacent to one another man apertured exterior side wall and providing conduits of approximately the same length for supplying combustion supporting air to the burner and withdrawing flue gases from the flue. However, the burner flame in systems of this type often is extinguished in spite of the fact that the air and flue gas conduits are of the same length and belief that, because the air inlet and flue gas outlet will be subjected to the same pressure fluctuations of ambient air, the pressure changes reflected back to the burner through both conduits will counteract one another so that the burner flame will always be maintained.

In combustion systems of the kind just described the outer end of the ambient air conduit and flue gas conduit extend through the apertured exterior side wall and project from the outer face of such wall and vertical screens are arranged in different ways to prevent strong winds perpendicular to the exterior wall from entering the open ends of the air conduit and flue gas conduit. Such screens also have been provided with openings in the top and bottom parts thereof to prevent gusts of wind parallel to the exterior side wall from producing pressure changes at the outer ends of the air and flue gas conduits which is objectionable. Besides not being able to maintain the burner flame under all adverse operating conditions encountered, the screens projecting from the exterior side wall are unsightly which also is objectionable.

SUMMARY OF THE INVENTION It is an object of our invention to provide an improved sealed combustion system of the kind referred to above for operating a gas-operated refrigerator in which the burner flame will be maintained under all operating conditions encountered. We accomplish this by providing a sealed combustion system in which the outlet for flue gases is disposed above the inlet for ambient air and the air inlet and flue gas outlet have the same cross-sectional areas and are flush with the outer surface of the exterior side wall of the space in which the refrigerator is disposed.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic representation in elevation of a gas-operated refrigerator and conduit connections therefor through which combustion supporting air is supplied to the gas burner and heated products of combustion are withdrawn from a flue coacting with the gas burner;

FIG. 2 is a vertical sectional view of parts shown in FIG. 3 which are like the conduit connections shown in FIG. 1;

FIG. 3 is a perspective view of the parts of the conduit connections shown in FIG. 2;

FIG. 4 is a diagrammatic representation like that shown in FIG. 1 illustrating another embodiment of the invention;

FIG. 5 is an enlarged fragmentary view of the conduit connections shown in FIG. 4 to illustrate details more clearly; and

FIG. 6 is a fragmentary elevational view taken at line 6-6 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 3, we have shown our invention in connection with a gas'operated refrigerator 10 which is supported on a floor 1 l of an enclosure or space 12 having an exterior side wall 14. The floor I1 and side wall 14 may form parts of a permanent building, such as a residential structure, for example, a mobile home like a trailer or camper, or a boat.

The refrigerator 10, which has a front access opening closed by a door 15, is adapted to be operated by gas-operated refrigeration apparatus which may be an absorption refrigeration system of a uniform pressure type and like that described in US. Pat. No. 3,512,371 to Sven A. Gurt and Karl H. Lindstrom, granted May 19, 1970. The refrigeration system comprises a plurality of parts which are interconnected in a wellknown manner and include a cooling unit (not shown) arranged to effect cooling of the interior of the refrigerator and a heat receiving part 16 having a heating flue 17 associated therewith. The heat receiving part 16, which is located at the rear of the refrigerator 10, is enclosed in an upright shell 16a through which the flue 17 extends.

In order to simplify the drawing, the parts of the refrigeration system other than the heat receiving part 16 have not been shown, such parts being well-known and their illustration not being necessary for an understanding of our invention. The disclosure in the aforementioned Gurt et al patent may be considered as being incorporated in this application, and if desired, reference may be made thereto for a detailed description of the refrigeration system.

A gas burner, which is diagrammatically shown at 18in FIG. 1 and is disposed within a hood 19, is positioned at the bottom of the heat receiving part 16 and projects its flame into the lower end of the flue l7. Combustible gas is delivered to the burner 18 through a conduit '29 from a suitable source of supply. Combustion supporting air is supplied to the burner 18 through a conduit 21 having its inner end connected to the hood l9 and its outer end terminating in an inlet 22 at an opening 23 in the exterior side wall 14.

When the burner 18 is ignited in any wellknown manner (not shown) and a combustible gas is supplied thereto through the conduit 20, combustion supporting air is supplied to the burner 18 through the conduit 21, such air being ambient air which is drawn into the conduit at its inlet 22. The hood 19 in which the burner 18 is disposed and the conduit 21 form a closed" or sealed" combustion system for the burner 18 in which all of the combustion supporting air is supplied through the conduit 21. Hence, the burner 18 does not operate in the open and so-called secondary" air to support combustion is not provided at the vicinity of the burner flame.

The heated gases flowing in the flue 17 effect heating of the heat receiving part 16 whereby the refrigeration system will function to promote cooling of the interior of the refrigerator. All of the heated products of combustion, which may be referred to as flue gases, are discharged from the upper end of flue l7 and conducted exteriorly of the space 12 through a conduit 24. The inner end of the conduit 24 is connected to the upper end of the flue 17 and the outer end thereof terminates at an outlet 25 at the opening 23 in the exterior side wall 14. Hence, the conduit 24 for the flue gases also forms a part of the sealed combustion system.

The air inlet 22 and outlet 25 for flue gases are immediately adjacent to one another and in abutting relation. The conduit 21 is of inverted U-shape having a closed end or section 21a and depending vertical legs or sections 21b and 210, the leg 21b terminating in the air inlet 22 and the leg 21c communicating with the burner hood 19. The conduit 24 also is of inverted U-shape having a closed end or section 240 and depending vertical legs 24b and 24c, the leg 24b terminating in the outlet 25 for the flue gases and the leg 24c communicating with the upper end of the flue 17.

The cross-sectional areas of the inlet 22 and outlet 23 and the conduit sections 21b and 24b connected thereto are greater than the cross-sectional areas of the conduit sections 21a, 21c and 24a, 240. As seen in FIG. 3, the air inlet 22 and outlet 25 for flue gases are rectangular with their major axes extending horizontally.

A rectangularshaped casing 26 having suitable partitioning can be employed to provide the air inlet 22 and flue gas outlet 25 and vertical conduit sections 21b and 24b communicating therewith, as shown in FIG. 3. The casing 26 fits snugly in the opening 23 in the exterior side wall 14 with the outer wall 26a of the casing flush with the outer surface or face of the side wall 14. Partitioning 27 of zig-zag shape is provided within the casing 26 which includes a vertical portion 27a between the front and rear walls thereof and horizontal portions 27b and 27c projecting in opposite directions from the vertical portion at its top and bottom edges, respectively.

The portion 270 bisects a cut-out section at the bottom of the front wall 26a to form the air inlet 22 and flue gas outlet 25. Conduit sections 22a and 24a are connected to the rear wall of the casing 26 at regions above and below the horizontal partition portion 27b. It will now be understood that the partitioning 27 in the casing 26 provides two vertical passageways therein which serve as the conduit sections 21b and 24b schematically shown in FIGS. 1 and 2.

A protective grate (not shown) can be mounted on the casing 26 over the air inlet 22 and flue gas outlet 25 to prevent insects and the like from entering the conduits 21 and 24. We have found that a slotted cover over the air inlet 22 and flue gas outlet 25 is not desirable because the burner flame may be extinguished when certain wind conditions prevail at the exterior side wall 14. An important feature of the embodiment being described is that the air inlet 22 and flue gas outlet 25 have substantially the same cross-sectional areas and are flush with outer surface of the exterior side wall 14.

We also have discovered that it is extremely important to provide an air inlet 22 and a flue gas outlet 25 each having a cross-sectional area greater than that of the heating flue 17. Further, to insure optimum performance of the embodiment of our invention shown in FIGS. 1, 2 and 3 and just described, the air inlet 22 and flue gas outlet 25 must be operatively associated with separate passageways or conduit sections 21b and 24b of substantially the same size or cross-sectional area. From the conduit sections 21b and 24b the other conduit sections 21a, 21c and 240, 240 connected to the hood l9 and flue 17, respectively, desirably are of smaller size or cross-sectional area.

We have illustrated another embodiment of our invention in FIGS. 4, and 6 in which parts similar to those shown in FIGS. 1, 2 and 3 are referred to by the same reference numerals. In FIGS. 4, 5 and 6 a conduit 121 extending from the exterior side wall 1 14 to the rear of the refrigerator has an inlet 122 for combustion supporting air at its outer end andis connected to the hood 19 of the burner 18 at its inner end. A conduit 124 extending from the exterior side wall 114 to the rear of the refrigerator 10 has an outlet 125 for flue gases at its outer end and is connected to the upper end of the flue 17 at its inner end.

A rectangular-shaped casing 126, which snugly fits in the opening 123 in the side wall 114, includes a horizontal partition 28 which divides the easing into top and bottom compartments or spaces 124b and 121b, respectively.

The front wall of the casing 126 is formed with cut-away sections which provide the air inlet 122 and flue gas outlet 125 which are flush with the outer surface of the exterior side wall 1 14. The conduit 121 for combustion supporting air includes a horizontal section 121a which is connected to the rear wall of the casing 126 at an opening therein which is below the partition 28. Hence, the forward end of the conduit section 121a is in communication with the upper part of the vertical passageway in the bottom compartment of the casing 126 which serves as the conduit section 121b. The rear end of the conduit section 121a is connected to the vertical conduit section 12lc which depends downward therefrom and is connected to the hood 19.

The conduit 124 for flue gases includes a horizontal section 1240 which is connected to the rear wall of the casing 126 at an opening therein adjacent to the top of the casing. Hence, the forward end of the duct section 124a is in communication with the upper part of the vertical passageway in the top compartment of the casing 126 which serves as the conduit section 124b. The rear end of the conduit section 124a is connected to the vertical conduit section 124C which depends downward therefrom and is connected to the upper end of the flue 17. Suitable protective gratings (not shown) may also be provided in the casing 126 at the regions of the air inlet 122 and flue gas outlet 125.

As seen in FIG. 6, the air inlet 123 and flue gas outlet are rectangular with their major axes extending horizontally and their cross-sectional areas are greater than the cross-sectional areas of the conduit sections 121a and 1240 connected to the rear wall of the casing 126. Further, the air inlet 122 is at the bottom of the bottom compartment of the casing 126 while the conduit section 122a projects rearward from the top part of the bottom compartment of the casing. Similarly, the flue gas outlet 125 is at the bottom of the top compartment of the casing 126 while the conduit section 124a projects rearward from the top part of the top compartment of the casing.

In the first-described embodiment of FIGS. 1, 2 and 3, the air inlet 22 and flue gas outlet 25 are in abutting relation and separated only by the horizontal portion 270 of the partition 27. In FIG. 6 it will be noted that the air inlet 122 and flue gas outlet 125 have the same cross-sectional areas and the same height a and are separated by the vertical distance d. The distance d desirably is in a range which is from 5 cm. to 15 cm. Hence, when both of the embodiments described are considered together, the vertical distance between the air inlet 22, 122 and flue gas outlet 25, 125 can be in a range of from 0 to 15 cm.

We claim:

1. In structure defining a space having an exterior side wall, heat-operated refrigeration apparatus disposed in said space, said refrigeration apparatus comprising a heat receiving part having a heating flue, a gas burner coacting with said flue, means for supplying combustible gas to said burner, first conduit means for conducting combustion supporting air to said burner, second conduit means for conducting flue gases from the upper end of said flue, said first and second conduit means and burner and flue being constructed and formed to provide a sealed combustion system in which all of the combustion supporting air is supplied to said burner through said first conduit means and all of the flue gases are withdrawn from said flue through said second conduit means, said exterior side wall being apertured, the end of said first conduit means removed from said burner being open and terminating in said apertured side wall and serving as an inlet for ambient air, the end of second conduit means removed from said flue being open and temtinating in said apertured side wall and serving as an outlet for flue gases, said flue gas outlet being disposed above said air inlet, and said air inlet and flue gas outlet having substantially the same cross-sectional areas and being substantially flush with the outer surface of said exterior side wall, said first conduit means including a vertically disposed section extending upward from said air inlet and said second conduit means including a vertically disposed section extending downward to said flue gas outlet.

2. Apparatus as set forth in claim 1 in which said apertured side wall has an opening therethrough and at least the vertically disposed section of said second conduit is in the vertical plane of said wall opening.

3. Apparatus as set forth in claim 1 which includes means defining two vertically extending spaces separated by partitioning, one of said spaces serving as the vertically disposed section of said first conduit and the other of said spaces serving as the vertically disposed section of said second conduit.

4. Apparatus as set forth in claim 3 in which said first conduit includes a horizontal section and said second conduit includes a horizontal section, each of said horizontal sections being in communication with a different one of said vertically extending spaces.

5. Apparatus as set forth in claim 1 which comprises a rectangular-shaped casing at the apertured side wall, said casing having partitioning defining said vertically extending sections of said first and second conduits, a wall of said casing flush with the outer surface of said exterior side wall being apertured to provide said air inlet and flue gas outlet at opposing sides of said partitioning.

6. Apparatus as set forth in claim 5 in which said partitioning comprises a zig-zag member having a vertical portion and horizontal portions projecting in opposite directions from said vertical portion at the top and bottom thereof, the air inlet and flue gas outlet being in abutting relation below and above said bottom horizontal portion at said apertured side wall of said casing.

7. Apparatus as set forth in claim 1 in which said vertically disposed section of said second conduit is flush with the outer surface of said exterior side wall and said vertically disposed section of said first conduit is at the rear of said vertically disposed section of said second conduit.

8. Apparatus as set forth in claim 1 in which said vertically disposed sections of said first and second conduits are both flush with the outer surface of said exterior side wall with said vertically disposed section of said first conduit below said vertically disposed section of said second conduit.

9. In structure defining a space having an exterior side wall,

heat-operated refrigeration apparatus disposed in said space, said refrigeration apparatus comprising a heat receiving part having a heating flue, a gas burner coacting with said flue, means for supplying combustible gas to said burner, first conduit means for conducting combustion supporting air to said burner, second conduit means for conducting flue gases from the upper end of said flue, said first and second conduit means and burner and flue being constructed and formed to provide a sealed combustion system in which all of the combustion supporting air is supplied to said burner through said first conduit means and all of the flue gases are withdrawn from said flue through said second conduit means, said exterior side wall being apertured, the end of said first conduit means removed from said burner being open and terminating in said apertured side wall and serving as an inlet for ambient air, the end of said second conduit means removed from said flue being open and terminating in said apertured side wall and serving as an outlet for flue gases, said flue gas outlet being disposed above said air inlet, and said air inlet and flue gas outlet having substantially the same cross-sectional areas and being substantially flush with the outer surface of said exterior side wall, each of said first and second conduit means including first vertically disposed portions at the immediate vicinities of said air inlet and flue gas outlet and second portions extending from said first portions to said burner and flue, respectively, the crosssectional areas of said air inlet and flue gas outlet being at least as great as the cross-sectional areas of said first vertically disposed portions of said first and second conduit means, and the cross-sectional areas of said first vertically disposed portions being greater than the cross-sectional areas of the second portions of said first and second conduit means.

10. Apparatus as set forth in claim 9 in which the first and second portions of each of said first and second conduit means is of inverted U-shape.

11. Apparatus as set forth in claim 9 in which the cross-sectional areas of said first vertically disposed portions of said first and second conduit means are at least equal to the crosssectional area of said flue. 

1. In structure defining a space having an exterior side wall, heat-operated refrigeration apparatus disposed in said space, said refrigeration apparatus comprising a heat receiving part having a heating flue, a gas burner coacting with said flue, means for supplying combustible gas to said burner, first conduit means for conducting combustion supporting air to said burner, second conduit means for conducting flue gases from the upper end of said flue, said first and second conduit means and burner and flue being constructed and formed to provide a sealed combustion system in which all of the combustion supporting air is supplied to said burner through said first conduit means and all of the flue gases are withdrawn from said flue through said second conduit means, said exterior side wall being apertured, the end of said first conduit means removed from said burner being open and terminating in said apertured side wall and serving as an inlet for ambient air, the end of second conduit means removed from said flue being open and terminating in said apertured side wall and serving as an outlet for flue gases, said flue gas outlet being disposed above said air inlet, and said air inlet and flue gas outlet having substantially the same cross-sectional areas and being substantially flush with the outer surface of said exterior side wall, said first conduit means including a vertically disposed section extending upward from said air inlet and said second conduit means including a vertically disposed section extending downward to said flue gas outlet.
 2. Apparatus as set forth in claim 1 in which said apertured side wall has an opening therethrough and at least the vertically disposed section of said second conduit is in the vertical plane of said wall opening.
 3. Apparatus as set forth in claim 1 which includes means defining two vertically extending spaces separated by partitioning, one of said spaces serving as the vertically disposed section of said first conduit and the other of said spaces serving as the vertically disposed section of said second conduit.
 4. Apparatus as set forth in claim 3 in which said first conduit includes a horizontal section and said second conduit includes a horizontal section, each of said horizontal sections being in communication with a different one of said vertically extending spaces.
 5. Apparatus as set forth in claim 1 which comprises a rectangular-shaped casing at the apertured side wall, said casing having partitioning defining said vertically extending sections of said first and second conduits, a wall of said casing flush with the outer surface of said exterior side wall being apertured to provide said air inlet and flue gas outlet at opposing sides of said partitioning.
 6. Apparatus as set forth in claim 5 in which said partitioning comprises a zig-zag member having a vertical portion and horizontal portions Projecting in opposite directions from said vertical portion at the top and bottom thereof, the air inlet and flue gas outlet being in abutting relation below and above said bottom horizontal portion at said apertured side wall of said casing.
 7. Apparatus as set forth in claim 1 in which said vertically disposed section of said second conduit is flush with the outer surface of said exterior side wall and said vertically disposed section of said first conduit is at the rear of said vertically disposed section of said second conduit.
 8. Apparatus as set forth in claim 1 in which said vertically disposed sections of said first and second conduits are both flush with the outer surface of said exterior side wall with said vertically disposed section of said first conduit below said vertically disposed section of said second conduit.
 9. In structure defining a space having an exterior side wall, heat-operated refrigeration apparatus disposed in said space, said refrigeration apparatus comprising a heat receiving part having a heating flue, a gas burner coacting with said flue, means for supplying combustible gas to said burner, first conduit means for conducting combustion supporting air to said burner, second conduit means for conducting flue gases from the upper end of said flue, said first and second conduit means and burner and flue being constructed and formed to provide a sealed combustion system in which all of the combustion supporting air is supplied to said burner through said first conduit means and all of the flue gases are withdrawn from said flue through said second conduit means, said exterior side wall being apertured, the end of said first conduit means removed from said burner being open and terminating in said apertured side wall and serving as an inlet for ambient air, the end of said second conduit means removed from said flue being open and terminating in said apertured side wall and serving as an outlet for flue gases, said flue gas outlet being disposed above said air inlet, and said air inlet and flue gas outlet having substantially the same cross-sectional areas and being substantially flush with the outer surface of said exterior side wall, each of said first and second conduit means including first vertically disposed portions at the immediate vicinities of said air inlet and flue gas outlet and second portions extending from said first portions to said burner and flue, respectively, the cross-sectional areas of said air inlet and flue gas outlet being at least as great as the cross-sectional areas of said first vertically disposed portions of said first and second conduit means, and the cross-sectional areas of said first vertically disposed portions being greater than the cross-sectional areas of the second portions of said first and second conduit means.
 10. Apparatus as set forth in claim 9 in which the first and second portions of each of said first and second conduit means is of inverted U-shape.
 11. Apparatus as set forth in claim 9 in which the cross-sectional areas of said first vertically disposed portions of said first and second conduit means are at least equal to the cross-sectional area of said flue. 